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Modified gravity theories with a nonminimal coupling between curvature and matter offer a compelling alternative to dark energy and dark matter by introducing an explicit interaction between matter and curvature invariants. Two of the main…

General Relativity and Quantum Cosmology · Physics 2025-10-29 Francisco S. N. Lobo , Tiberiu Harko , Miguel A. S. Pinto

We investigate the possibility of gravitationally generated particle production via the mechanism of nonminimal torsion--matter coupling. An intriguing feature of this theory is that the divergence of the matter energy--momentum tensor does…

General Relativity and Quantum Cosmology · Physics 2021-07-06 Tiberiu Harko , Francisco S. N. Lobo , Emmanuel N. Saridakis

In this work, one examines how the presence of a non-minimal coupling between the spacetime curvature and matter affects the evolution of cosmological perturbations around a homogeneous and isotropic Universe and hence the formation of…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Orfeu Bertolami , Pedro Frazão , Jorge Páramos

We consider the possibility of a gravitationally induced particle production through the mechanism of a nonminimal curvature-matter coupling. An interesting feature of this gravitational theory is that the divergence of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2015-08-31 Tiberiu Harko , Francisco S. N. Lobo , José P. Mimoso , Diego Pavón

We explore a cosmological model in which dark matter is non-minimally coupled to gravity at the fluid level. While typically subdominant compared to Standard Model forces, such couplings may dominate dark matter dynamics. We show that this…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Samuele Silveravalle , Andrea Lapi , Francesco Benetti , Stefano Liberati

We investigate the consequences of non-minimal gravitational coupling to matter and study how it differs from the case of minimal coupling by choosing certain simple forms for the nature of coupling, The values of the parameters are…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Shruti Thakur , Anjan A Sen , T. R. Seshadri

We propose a phenomenological model in which a non-minimal coupling between gravity and dark matter is present in order to address some of the apparent small scales issues of \lcdm model. When described in a frame in which gravity dynamics…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-24 Dario Bettoni , Valeria Pettorino , Stefano Liberati , Carlo Baccigalupi

Dark photons are a theorized massive spin-1 particle which can be produced via various mechanisms, including cosmological gravitational particle production (GPP) in the early universe. In this work, we extend previous results for GPP of…

High Energy Physics - Theory · Physics 2024-09-20 Christian Capanelli , Leah Jenks , Edward W. Kolb , Evan McDonough

The lack of energy conservation introduces new particle processes in curved spacetime that are forbidden in flat space. Therefore one has to be very cautious about using the results calculated in Minkowskian space in early universe…

General Relativity and Quantum Cosmology · Physics 2018-08-22 Juho Lankinen , Iiro Vilja

An interesting cosmological history was proposed by Prigogine {\it et al.} who considered the Universe as a thermodynamically open system. This scenario is characterized by a process of matter creation, which corresponds to an irreversible…

General Relativity and Quantum Cosmology · Physics 2015-08-14 Francisco S. N. Lobo , Tiberiu Harko , José P. Mimoso , Diego Pavón

We examine an extension of General Relativity with an explicit non-minimal coupling between matter and curvature. The purpose of this work is to present an overview of the implications of the latter to various contexts, ranging from…

General Relativity and Quantum Cosmology · Physics 2014-01-20 Orfeu Bertolami , Jorge Páramos

We construct an extension of f(T) gravity with the inclusion of a non-minimal torsion-matter coupling in the action. The resulting theory is a novel gravitational modification, since it is different from both f(T) gravity, as well as from…

General Relativity and Quantum Cosmology · Physics 2014-07-01 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

In this paper we discuss a class of models that address the issue of explaining the gravitational dynamics at the galactic scale starting from a geometric point of view. Instead of claiming the existence of some hidden coupling between dark…

General Relativity and Quantum Cosmology · Physics 2011-11-10 Dario Bettoni , Stefano Liberati , Lorenzo Sindoni

We point out that the inflaton inevitably couples to all non-conformally coupled matters gravitationally through an oscillation in the Hubble parameter or the cosmic scale factor. It leads to particle production during the inflaton…

High Energy Physics - Phenomenology · Physics 2015-06-02 Yohei Ema , Ryusuke Jinno , Kyohei Mukaida , Kazunori Nakayama

In this study, we explore how a non-minimal coupling between dark matter and gravity can affect the behavior of dark matter in galaxy clusters. We have considered the case of a disformal coupling, which leads to a modification of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-30 Saboura Zamani , Vincenzo Salzano , Dario Bettoni

We study a theory which generalizes the nonminimal coupling of matter to gravity by including derivative couplings. This leads to several interesting new dynamical phenomena in cosmology. In particular, the range of parameters in which…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Luca Amendola

In this work the phenomenology of models possessing a non-minimal coupling between matter and geometry is discussed, with a particular focus on the possibility of describing the flattening of the galactic rotation curves as a dynamically…

Astrophysics of Galaxies · Physics 2015-05-18 Orfeu Bertolami , Jorge Páramos

We consider a gravitational theory with an additional non-minimal coupling between baryonic matter fields and geometry. The coupling is second order in the energy momentum tensor and can be seen as a generalization of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2021-04-19 Shahab Shahidi

One of the most interesting and current phenomenological extensions of General Relativity is the so-called $f (R)$ class of theories; a natural generalization of this includes an explicit non-minimal coupling between matter and curvature.…

General Relativity and Quantum Cosmology · Physics 2011-11-16 J. Páramos

We consider an extension of standard General Relativity in which the Hilbert-Einstein action is replaced by an arbitrary function of the Ricci scalar, nonmetricity, torsion, and the trace of the matter energy-momentum tensor. By…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Tiberiu Harko , Nurgissa Myrzakulov , Ratbay Myrzakulov , Shahab Shahidi
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